The Air Force Space Surveillance System, colloquially known as the Space Fence, is a multistatic radar system that detects orbital objects passing over America. It is a component of the US space surveillance network, and is claimed to be able to detect objects as small as 10 cm (four inches) at heights up to 30,000 km (15,000 nautical miles.) Although formerly operated by the U.S. Navy and known as NAVSPASUR (short for "Naval Space Surveillance"),[1] command passed to the Air Force 20th Space Control Squadron on October 1, 2004.[2] The operation's headquarters are at Dahlgren, Virginia, and radar stations are spread out across the continental United States at roughly the level of the 33rd parallel north.
There are three transmitter sites in the system:[3]

The master transmitter at Lake Kickapoo is said to be the most powerful continuous wave (CW) station in the world, at 768 kW radiated power on 216.97927 MHz. Overhead imagery (see coordinates given above) of the Gila River and Jordan Lake sites suggests that the original design called for antennas of twice the present length with, presumably, greater radiated power.
There are 6 receiving stations:[3]

San Diego, California (
32°34′42″N 116°58′11″W)

Elephant Butte, New Mexico (
33°26′35″N 106°59′50″W)

Red River, Arkansas (
33°19′48″N 93°33′01″W)

Silver Lake, Mississippi (
33°08′42″N 91°01′16″W)

Hawkinsville, Georgia (
32°17′20″N 83°32′10″W)

Tattnall, Georgia (
32°02′35″N 81°55′21″W).

The receiving stations at Elephant Butte and Hawkinsville are considered to be "High Altitude" stations with longer and more complex antenna systems that are designed to see targets at higher altitudes than the other four receiving stations.